The present invention relates to a contents control system for controlling reproduction and storage of contents, and more particularly to a technique effectively applied to a contents control system for controlling reproduction on the receiving side of contents circulated by a wired network or broadcasting wave, storage of the contents in a recording medium inside a receiving apparatus and retransmission of the contents to another receiving apparatus.
Conventionally, digital contents such as still picture, video data and audio data is presented to users by way of a communication medium such as Internet or digital broadcasting, or a recording medium such as CD-ROM or DVD-ROM. The digital contents as above has such a characteristic that it can be duplicated easily. Accordingly, it is conceivable that the third party can get the contents unfairly or without authorization. Under the circumstances, with a view to enable only persons having authorized right to utilize the contents, reproduction control and copy control of the digital contents utilizing the digital watermark technique have hitherto been proposed.
The digital watermark technique is described in “General Quality Maintenance Module for Motion Picture Watermarking” by I. Echizen, H. Yoshiura, T. Arai, H. Kimura and T. Takeuchi, IEEE Transactions on Consumer Electronics, Vol.45, No.4, pp.1150-1158, November 1999.
Taking image data and video data, for instance, a conventional technique concerning control of such contents is described in “Request for expressions of interest” on DVD CCA's website, Copy Protection Technical Working Group, 2001. In the conventional technique, however, object contents is stored in a medium such as DVD-ROM or DVD-RAM on the presupposition that reproduction of media type contents and control of its copy to a medium are carried out by a dedicated unit such as DVD player and recorder.
On the other hand, by the aid of speedup of network and advance of digital broadcasting technology, the conventional media type contents is forwarded and distributed by way of a broadcasting wave or network. The forwarded contents is received by a personal computer (PC), settop box (STB) or the like, and can be applied with various processes such as playback and edition of the contents, selection of channels of different cameras and bi-directional communication by means of the transmitting/receiving apparatus. While various kinds of processes can be applied to contents on the network and broadcasting wave by the general-purpose transmitting/receiving apparatus as above, the application of the conventional technique for performing only reproduction of media type contents and control of its copy to a medium to the contents transmitting/receiving apparatus on the network and broadcasting wave raises a problem that operation by the user for contents utilization based on rights characteristics is limited and various operations of contents depending on various kinds of rights characteristics become impossible.